Al-Hezaimi Khalid, Iezzi Giovanna, Rudek Ivan, Al-Daafas Abdullah, Al-Hamdan Khalid, Al-Rasheed Abdulaziz, Javed Fawad, Piattelli Adriano, Wang Hom-Lay
1 College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
J Oral Implantol. 2015 Apr;41(2):188-95. doi: 10.1563/AAID-JOI-D-13-00027. Epub 2013 May 28.
In untreated extraction sockets, buccal bone remodeling compromises the alveolar ridge width. The aim of this study was to histologically assess the efficacy of using a dual layer of membranes (high-density polytetrafluoroethylene [dPTFE] placed over collagen) for ridge preservation in fresh extraction sites. Eight beagle dogs were used. After endodontic treatment of mandibular bilateral second (P2), third (P3), and fourth (P4) premolars, mandibular bilateral first premolars and distal roots of P2, P3, and P4 were extracted atraumatically. Animals were randomly divided into 4 treatment groups. group 1, the control group, received no treatment; in group 2, allograft was placed in the alveolum and the socket covered with dPTFE membrane; in group 3, allograft was placed in the alveolum, the buccal plate was overbuilt with allograft, and the socket was covered with dPTFE membrane; in group 4, allograft was placed in the alveolum and covered with dual layer of membranes (dPTFE placed over collagen). No intent of primary closure was performed for all groups. After 16 weeks, the animals were sacrificed and mandibular blocks were assessed histologically for buccolingual width of alveolar ridge, percentage of bone formation and bone marrow spaces, and the remaining bone particles. The buccolingual width of the alveolar ridge was significantly higher among sockets in group 4 than in group 1 (P < .05). the amount of newly formed bone in each socket was higher in extraction sockets in group 4 than in groups 1, 2, and 3 (P < .001). A significant difference was found in the percentage of bone marrow spaces among all groups (P < .001). No significant difference was found in the number of nonresorbed bone particles among the groups. Using a dual layer of membrane was more effective in ridge preservation than conventional socket augmentation protocols.
在未经处理的拔牙窝中，颊侧骨重塑会损害牙槽嵴宽度。本研究的目的是通过组织学评估在新鲜拔牙位点使用双层膜（高密度聚四氟乙烯[dPTFE]置于胶原之上）进行牙槽嵴保存的效果。使用了8只比格犬。对下颌双侧第二前磨牙（P2）、第三前磨牙（P3）和第四前磨牙（P4）进行牙髓治疗后，无创性拔除下颌双侧第一前磨牙以及P2、P3和P4的远中根。将动物随机分为4个治疗组。第1组为对照组，不进行治疗；第2组，将同种异体移植物置于牙槽窝内，拔牙窝用dPTFE膜覆盖；第3组，将同种异体移植物置于牙槽窝内，用同种异体移植物重建颊侧板，拔牙窝用dPTFE膜覆盖；第4组，将同种异体移植物置于牙槽窝内，并用双层膜覆盖（dPTFE置于胶原之上）。所有组均不进行一期缝合。16周后，处死动物，对下颌骨块进行组织学评估，观察牙槽嵴的颊舌径宽度、骨形成百分比和骨髓腔，以及剩余的骨颗粒。第4组拔牙窝的牙槽嵴颊舌径宽度显著高于第1组（P < 0.05）。第4组拔牙窝中每个拔牙窝新形成的骨量高于第1组、第2组和第3组（P < 0.001）。所有组之间骨髓腔百分比存在显著差异（P < 0.001）。各组之间未吸收骨颗粒的数量无显著差异。使用双层膜在牙槽嵴保存方面比传统的拔牙窝增强方案更有效。
